Compressing apparatus



Feb. 9, 1937. A. A. M coRMAcK ,76

COMPRESSING APPARATUS Original Filed Dec. 25, 1952 4 Sheet-Sheet 1 Feb. 9, 1937. A. A, M coRMA'cK COMPRESSING APPARATUS Original Filed Dec. 23, 1932 4 Sheets-Sheet 2 A. A. M CORMACK COMPRESSIN G APPARATUS Original Filed Dec. 23, 1932 4 Sheets-Sheet 3 Feb. 9, 1937. A. A. Mcco cK 2,069,767

COMPRESSING APPARATUS Original Filed Dec. 23, 1932 4 Sheets-Sheet 4 Patented Feb. 9, 1937 UNITED I STATES PATENT OFFICER oomranssmc mans'ros Alex- A.. McCormack, Dayton, Ohio, assignor, by

me ne assignments, to General Motors Corporation, a corporation of Delaware Application December 2:, 1932, Serial No. 648,705 Renewed March 20, was

21 Claims.

unimproved form of unloader for the motor compressor unit for reducing the starting torque of a the unit during the starting period of the motor. 15 Another object of this invention is to provide a motor-compressor unitin which an oscillating type of compressor is enclosed under a cover plate in such a manner as to insurethorough lubrication of the? moving parts of the unit.

Another object-of this invention isto provide an improved construction in which the motor and compressor are resiliently mounted within a sealed casingand'in which one of the refrigerant pipesleading to the compressor is secured to the casing and to the resiiient frame carrying the motor and compressor in a manner to reduce vibration in the unit.

Further objects and advantages of thc present invention will be apparent from the following description, reference being had to the accompanying drawings, wherein a preferred form of the present invention is clearly shown. I

In the drawings: Y v Fig. l is a diagrammatic representation of an apparatus embodying features of this invention; Fig. 2 is a vertical cross-sectional view of a motor-compressor unit embodying features of this invention, the cross section being taken along the line 2-4 -of Fi .3;

Fig. 3 is a horizontal cross sectional view of the motor-compressor unit taken along the line 31-3 oi P18. 2; i

Fig. 4 isanother'horizontal cross sectional view 46 looking upwardly along the line 4-4 of Fig. 2;

improved check valve, said view being taken along the line 5-5 of Fig. 4; i

Fig. 6 is a horizontal crosssectional of a portion of the compressor showing a detail of the divider block; i

Fig. 7 is a vertical cross sectional view of .one

form of resilient mounting for the motor-compressor frame;

55 Fig. 8 is a vertical Fig. 5 isa vertical cross. sectional view of my cross sectional view of a modified form of resilient mounting the line H of Fig. 9; and i Fig. 9 is a horizontal cross sectional view of the, mounting shown in Fig.8. A refrigerating apparatus embodying features 5 of this invention includes, in general, a motorcompressor unit having a two-piece, hermetically sealed casing ll shown in Fig. 1 diagrammatically by a dotted line and being in actual form cylintaken along drlcal in shape as shown in the'other figures. 10

The motor-compressor unit includes a motor generally indicated at H. having stator windings l2,

l3, and I4 and a rotor II. The rotor ii is connected by a shaft I! to a compressor ll. The compressor is compresses refrigerant anddischarges the same through the pipe I! to the condenser where refrigerant is condensed and from; which it is discharged into thereceiver 2|. From thence theliquid refrigerant flows through the pipe 22 to the evaporator 23, which may be of go the well-known that controlled inlet valve type.- The refrigerant evaporated at 23 flows through the pipe 24 to the intake of the compressor.

The motor-compressor unit may operate intermittently in accordance with temperatures 25 prevailing in the apparatus and, for example, it may be controlled by a snap switch II operated by a bellows I! which is responsive to the refrigerant pressure in the pipe 24.. The snap switch "opens and closes the electric circuit which in turn energizes the motor of the unit.

An improved starting controlmay be provided for the motor of the unit. To this end, the stator winding if maybe of the well-known starting winding type, the stator winding ll may be of the well-known running winding type, these two windings being common in the usual split phase motor and forming the energizing stator of the motor. The winding I! may be an auxiliaryor generator winding, the windings i2, i3, and il being arranged in a manner similar to windings l, 5, and I described in the patent to Jennings 1,315,965, September 16, 1919. when the motor starts, the winding i2 is energized until the motor attains sufficient speed to operate under the running winding ll, and I have provided an improved control for energizing and deenergizing the starting winding II to insure a proper startof themotor. "Io this end, the lead 21 of the electric circuit is connected to the contactsll of the starting relay 2!. .The contacts 28 are connected to the lead ll which passes through lead-in plug lla andis connected to the starting winding If. Thewinding I! is connected to the'common lead Ii which passes through'ss lead-in plug lid. The running winding circuit includes the branch lead 33, solenoid fl, branch "a, running winding Hand common lead II. The solenoid 34 of the starting relay" is connected to. generator winding I! which is enersized by the rotation of rotor l5. Any suitable circuitmay be .used to permit a current flow between winding I3 and the solenoid 3|; but in order to reduce the number of lead-in plugs in casing II, the winding ll may be connected by line with branch 33 before it passes through the lead-in plug 36. From the branch If, .the current flows through lead 21, solenoid I4, line 31, plug ll to the winding II.

The starting winding control operates as follows: When the switch 25 is closed current flows through the starting winding, the circuit includ-{ ing lead 21, contact ",lead 30, winding l2 and lead ll. Simultaneously current flows through the runnii... winding H, the circuit including the branch 33, solenoid i0, branch "a, winding l4,

andbranch ll. The fiow of current through the windings I and H starts the motor and when sufficient speed has been attained to permit the motor to operate unwinding ll alone, the cur-.-

rent generated in winding it reaches a value sufiicient to energize the solenoid 34 and open the contacts".

The motor. and the compressor may be resiliently mounted within the casing I I), and, to this end, they are supported on a frame 40 which in turn is resiliently mounted invthe casing Ill by means of springs ll placed in the upwardly directed holes 42 in the frame 40. These springs 4i rest on individual shelves If mountedon .the casing l which are provided with buttons 44 whichposition the springs on the shelves 43. The shelves 4! may be providedwith resilient stops to limit the permissible vibration of the motor and compressorr The compressor is provided with a cover plate 4! within the casing II which insuresproper lubrication of the'compressor and permits the lubricant and compressed refrigerant to be forced through the hollow shaft II to the lower portion of thecasing. The cover plate 48 is secured to theframe II by means of bolts 41.

cylinder ii, and the refrigerant is delivered to.

The compressor includes an oscillating plate l8 provided with a downwardly directed cylindrical extension 49. .The'plate 'restson the table 50 of the frame ligand the cylindrical extension ll operates within the cylinder, II formed in the frame Al. The plate 48 and cylinder 49. are given an oscillating movementby the eccentric 52 having a ball bearing drive 53 with the'plate 48. The plate 48 is prevented from rotating but is permitted to oscillate by a divider block 54 which oscillates about a pin 65 and has a cylindrical cooperating surface 86 concentric with the axis of the'pin 55. the surface 56 cooperating with a similar, cylindrical surface on the frame 10. In this manner a compressing chamber is formed between the cylindrical extension 49 and. the

in II, the lubricant flows upwardly and lubricates these surfaces. The lubricant which finds its way to these surfaces in time, is discharged through the flapper valve "along with the re-; frigerant and a certain portion'of the lubricant remains to lubricate the various moving surfaces of the compressor while the refrigerant and a portion of the lubricant passes through the central opening Ill in the shaft I! to the lower radial discharge openings II at the lower portion of the shaft H. The central opening it is plugged at 12 to prevent discharge of, lubricant through the end of the shaft.

An improved unloader for reducing the starting. torque is provided. This includes a check valve "for the intake of the compressor which check valve includes a valve plate having a stem 18, the plate resting on a valve seat 11. The gas returning from the evaporator 23 passes through the pipe 2| past'the annulus l8 and through the pipe lsto the intake of the com pressor. When the compressor stops, by reason of the opening of the snap switch 2!, electric current stops flowing through and deenergizes the solenoid 80 which is in serieswith the running winding I4. The deenergization of the coil Oil.

opens a valve 80a in the line 8| which permits compressed refrigerant to. flow through theiine 8| to the seat 11 and forces the valve plate 15 firmly against the annulus I8 thussealing the refrigerant in the motor-compressor unit from the refrigerant in the evaporator 23 thus preventing back flow of refrigerant to the evaporator. This action also equalizes the refrigerant pressures on the intake and discharge of the compressor, and the volumetric capacityof pipe 19 is such that the compressor attains its normal running speed before an appreciablepressure differential can be developed. Thus the compressor is unloaded during the starting period. The solenoid control 80 heretofore described is more fully shown and described in the copending application of George C. Pearce, Serial No. 640,316, filed 0012429, 1932,

to which'reference is hereby made, if necessary, for further disclosure thereof.

One of the pipes leading to the compressor may be connected to the casing l0 and to the compressor and may be coiled in the casing to preventundue crystallization of the pipe. In this particular embodiment, the intake pipe I9 is spirally coiled about the lower portion of the casing l0 and is then secured by the bridge 85 so that the pipe is firmly secured to the resiliently mounted portion of the mechanism coaxially with the shaft II. This reducesthe strains at the connection of the pipe I! with the frame at the point 86 where the passage 51 leads to the compressing chamber heretofore described.

A modified form of resilient mounting is shown in 'Figs. 8 and 9 in which a U-shaped spring 90 is securedby the bolt 8| to the block 92 which in turn is secured to the casing ID. The other end might be adopted,'all coming within the scope of the claims which follow.

What is claimed is as follows: i 1. Compressing apparatus comprising a compressor having a gas intake and a gas discharge, it

means for driving said compressor, an unloader for said compressor including a downwardly directed valve seat on said gas intake, a check valve having an upwardly directed surface engaging said valve seat for preventing backward flow of gas through said. gas intake, a gas conduit connected to the high pressure side of said compressor and having discharge means for upwardly actuating said check valve, and means for closing said conduit during the running periods of said compressor and for opennig said conduit during the idle periods of said compressor.

2. Compressing apparatus comprising a sealed casing, a compressor supported in said casing, a motor in said casing for driving said compresso a hollow drive shaft connecting said motor and compressor and extending through said compressor, a cover plate over one end of said compressor into which said compressor discharges. said drive shaft having an opening into the space enclosed by said cover plate and discharging the compressed fluid on the other side" of said compressor into said casing.

i 3. Compressing apparatus comprising a sealed casing, a compressor supported in saidcasing. a motor in said casing for driving saidcompressor, a hollow drive shaft connecting said motor and compressor and extending throu h said motor, a cover plate over one end of said compressor into which said compressor discharges, said drive shaft having an openinginto the space enclosed by said cover plate anddlsiiharging the compressed fluid through said motor into said casing.

4. Compressing apparatus comprising a sealed casing, a compressor and motor-having a drive shaft drivingly connecting said compressor motor within said casing, a. frame on which said motor and compressor aremounted, resilient-supports in said casing for said frame, a fluid conduit passingthrough said casing and sealedto said compressor, said conduit having a spiral formation in said casing and being secured to said frame sub-- stantially in alignment with said drive shaft.

5. Compressing apparatus comprising a casing, a compressor within said casing discharging com-' pressed fluid into the high pressure portion of said casing, a suction connection between the intake of said compressor and the exterior of said casing, a check valve in said suction connection, a passageway from said high pressure portion dischar ing against said check valve, a valve in said passageway, an electric motor driving said compressor,

a solenoid structure closing said last named valve when said electric motor is energized and for opening said last named valve when said motor is deenergised.

' 6. Compressing apparatus comprising a casing, a compressor within said casing discharging compressed fluid into the pressure portion of said casing, a suction connection between. the intake of said compressor and the exterior of said casing, a check valve in said suction connection, a passageway from said high pressure portion discharging against said check valve, a valve in said passage- 7 way, an electric motor in said casing driving said compressor, a solenoid structure closing said last named valve when said electric motor is eastglzed and for opening said last named valve when said motor is deenergized.

'I. Compressing apparatus comprising a compressor having a gas intake and a gas discharge, means for driving said compressor, an unloader for said compressor including a three-way valve having conduits in communication with the gas intake and the gas discharge of the compressor, and with a source of gas to be fed to said intake, and means responsive to the gas pressure in one of said conduits for operating said valve to connect said gas intake either with the gas discharge or with said source of gas.

8. Compressing apparatus comprising a compressor having a gas intake and a gas discharge, means for driving said compressor, an unloader for said compressor including a three-way valve 'having conduits-in communication with the gas intake and the gas discharge of the compressor and with a source of gas to be fed to said intake, and means responsive to the gas pressure in the conduit communicating with the gas'discharge for operating said valve to connect said gas intake either with the gas discharge or with said source of gas.

9. Compressing apparatus comprising a compressor having a gas intake and a gas discharge,

means for driv ng said compressor, an unloader' for said compressor including a three-way valve having conduits in communication with the gas intake and the gas discharge of the compressor and with a source of gasto be fed to said intake, and means responsive to the gas pressure in one of said conduits for operating said valve to connect said gas intake either with the gas discharge or with said source of gas, and means for controlling the pressure in said one conduit.

l0. Compressing-apparatus comprising a compressor having a gas intake and ages discharge, means for driving said compressor, an unloader for said compressor including a three-way valve having conduits in communication with the gas intake and with the gas discharge of the compressor and with a source of gas to'be fed to said intake, and means responsive to the gasl 'essure in one of said conduits for operating said valve to connect said gas intake either with the gas discharge or with said source of gas, and valve means for controlling the pressure in said one conduit.

11. Compressing apparatus comprising a pressor having a gas intake and a gas discharge, means for driving said compressor, an unloader for said compressor including a three-way valve having conduits in communication with the gas intake and the gas discharge of the compressor and with a source of gas to be fed to said intake, and means responsive to the gas pressure in the conduit communicating with the gas discharge for operating said valve to connect said gas intake either with the gas discharge or with said source of gas, and means for controlling the pressure in the conduit communicating with the gas discharge.

l2. Compressing apparatus-comprising a compressor having a gas intake and a gas discharge, means for driving said compressor, an unloader for said compressor including a three-way valve having conduits in communication with the gas intake and the gas discharge of the compressor and witha source of gas to be led to said intake, and means responsive to the gas pressure in the conduit communicating with the gas discharge for operating said valve to connect said gas intake either with the gas discharge or with said source of gas, and valve means for controlling the pressure in the conduit communicating with the gas discharge.

18. Compressing apparatus comprising a sealed casing, a motor in said casing, a compressor in said casing driven by said motor and having a discharge adjacent one end of said casing, means forming a closed conduit for conducting compressed gas to the opposite end of said casing, and an outlet from said casing adjacent said one end thereof.

comv 14. Compressing apparatus comprising a sealed casing, a motor in said casing, a compressor in said casing driven by said motor andhaving a discharge adjacent the top of said casing, means forming a closed conduit for conducting compressed gas tothe lower end of said casing, and

an outlet, from said, adiacentthe top 15. Compressingapparatus comprising an electric motor; a compressor driven-thereby and having a gas intake anda gas discharge, means,

aooavav pressor including a three-way valve having con+ duits in communicationwith the gas intake and with ;the gas discharge of thcompressor and "with a source oigas to be fed to said intake,

'and'means responsive to starting electricalconfor driving said :compressor. unloader ior, 5

said compressor including a three-way valve havingconduits in communication with the gasin take and the gas discharge or the compressor and with a source of gas tobe red to said intake,

and means responsive to starting electrical conditions ln said motor and the gas pressure in, one of said conduits for operatingsalid valve to connect said gasintake either with thegas" discharge or with said source of gas.,

conduits incommunication with-the gas mt k tions in said conduit communicating with; the gas discharge,

' in "operating saidvalve'to connect saidgas'inu take either with the gas discharge or with said I ing a gas intake r l'l. Compressing apparatus comprising an elec- I tric motonxa compressor driventherehy and'havand a gas discharge,means for" driving'said' compressoryan unloader for said compressor including a three-way, valve having conduits in communication'with the gas intake and the gas discharge of; the-compressor and with a source oi='gas to'befed to said intake,

and means responsive to-st'arting electrical cons ditions insaid motor and the gas pressure in one of said conduits for operating said valve to connect saidgaslntake eitherwith the gas discharge or with said source of gas, and meansior controlling the pressurein said one conduit.

l8. Compressing apparatus comprising an electric motor, a compressor driven thereby and havditions insaldmotor and the gas pressure in one {of aidiconduits for operating said valve tolcon nect said gas intake eitherwith the gas discharge or with said source oi'igas, and valve means for controlling, the pressure in said one conduit. 1 19. Compressing apparatus comprising an electric motor, a compressor driven thereby and hav-- ing a gas intake and a gas. discharge, means for driving said compressor, an unloader for said compressor including a three-way valve having 7 conduits in communication with the gas intake, 1 Land the, gas discharge 0! the compressor and with a source of gas to be fed to said intake; and means r V i-gfresponsive to starting electrical conditions in said. 16.; Compressing lPDflififillBfr comprising an electric motor. a compressor driven thereby and motor and the gas pressure in the conduit comhaving a EBSIDtQkQSDd SSKRS discharge, means for driving said compressor; an unloader-iorsaid q 7 compressor includlng a three way ivaiveliaving -meansior controlling ,the ressure in thexconduit and the [gas discharge of. the" comprasorland with asource-oi gas to, be fed to saidintake, and':.

means responsive to starting electrical condi-iil;

. pressor including a three"-way valve havingtcons duits in communication with the gasintake and said valve-to connect said said valve to connect said-gas intake either, with the gas discharge or with said source of gas, and

communicatingwwitnr the gaszdischarge.

,ingagas'intaknudist discharg means for motor and the gas pressure in the 20. Ccmpressingapparatus comprisingan elec tric motor; a comp iessordriven thereby and hav- 3,

driving said compressor, an unloader for said comthegasdischarge oi the'compressor and with a source of gas to befed to said intake, and means responsive to starting electrical conditions in said motor and the gas pressure in the conduit communicatingrwith the gas discharge for. operating M gas intake either with the gas discharge orv with valve meanslior controlling the pressure in the conduit communicating with the gas discharge.

7 2l.-Compressing apparatuscomprisingasealed' casing, a m torin saidvcasing, a compressor in said casing driven by said motor and having a dissaid source of gas, and

charge adjacent one-end, of said casing, means a i'orminga closednconduit for conducting compressed gas to the oppositetendof said casing,

and an outlet from said casingadiacent said first namedendthereoifiwq A a a ALE XA. McCORMACK. 

